QAA, Lebanon -- Quietly but inexorably, a human tide has crept into Lebanon, Syria's smallest and most vulnerable neighbor.
As Syrians fleeing civil war pour over the border, the village priest here, Elian Nasrallah, trudges through muddy fields to deliver blankets. His family runs a medical clinic for refugees. When Christian villagers fret about the flood of Sunni Muslims, he replies that welcoming them is "the real Christianity."
But the priest and his parishioners cannot keep up. The United Nations counts more than 305,000 Syrian refugees in Lebanon, but local officials and aid workers say the actual number is about 400,000, saturating this country of four million.
The Lebanese government -- by design -- has largely left them to fend for themselves. Deeply divided over Syria, haunted by memories of an explosive refugee crisis a generation ago, it has mostly ignored the problem, dumping it on overwhelmed communities like Qaa.
So far, Lebanon's delicate balance has persevered, but there is a growing sense of emergency.
Sectarian tensions are rising. Fugitive Syrian rebels in border villages have clashed with Lebanese soldiers. The government's anemic response has delayed international aid. Local volunteers are running out of cash and patience.
And the battle for Damascus, Syria's capital, has barely begun. Should fighting overwhelm that religiously and politically mixed city of 2.5 million a half-hour drive from Lebanon, the Lebanese fear a cataclysm that could sweep away their tenuous calm.
"There is a limit to what the country can handle," said Nadim Shubassi, mayor of Saidnayel, a Sunni town now packed with Syrians. "Maybe we have reached this limit now."
Lebanon's refugee crisis does not match the familiar image of vast, centralized tent camps and armies of foreign aid organizations. It is nowhere, and everywhere. Displaced Syrians seem to fill every nook and cranny: half-finished cinder block houses, stables, crowded apartments.
It is easy to miss them, until a second glance. Drying laundry peeks from construction sites. Bedsheets hang in shop windows, concealing stark living spaces. Daffodil sellers, shoeshine men, women and children begging in Beirut -- all incant, "Min Suria." From Syria.
At first, most refugees -- mainly Sunnis, like most of the rebels fighting Syria's government -- headed for friendly Sunni areas. Now, those communities are swamped and resentful, and Syrians are spreading to places where they fit less comfortably, from Christian mountain villages to the Mediterranean city of Tyre in the southern Shiite Muslim heartland.
They are moving, with some trepidation, into Qaa, in the northern Bekaa Valley, the territory of the powerful Shiite militia Hezbollah, which is allied with Syria's government and, to many refugees, just as fearsome.
As they flee increasingly sectarian killing, Syrians layer their fears onto those of a country deeply scarred by its own generation-long sectarian civil war. They are testing, yet also relying on, the fragile yet flexible balance that has endured here, punctured by occasional fighting, since Lebanon's war ended 22 years ago.
In Baalbek, a Hezbollah stronghold where a poster of the Syrian president, Bashar al-Assad, grins down on a busy street, refugees turn to Sawa, a community group that views helping them as embodying its nonsectarian mission. Still, they rattle Abbas Othman, a Sawa member.
"We are worried they will bring their civil war here," he said.
One recent evening in Qaa, Mr. Nasrallah, the priest, stood outside a burlap shack that sheltering a Syrian family of 12. They clamored around him; they had eaten only potatoes that day. Cold crept in as a blue dusk fell. One man implored, "You are responsible for us!"
The priest threw up his hands.
"It's wartime," he said. "Is the government doing its job or not?"
Lebanese decision-makers wanted it this way, at first. A year ago, just 5,000 Syrians had fled here, and Hezbollah, Lebanon's most powerful political party, denied any sense of crisis.
The government did not just stand aside, it often undermined aid. Donated supplies went undelivered. Small grants required signatures from the prime minster. During a fierce snowstorm, security forces blocked delivery of tents until a cabinet member intervened.
"Our government worried too much about politics," said Emad Shoumari, mayor of a majority-Sunni town, Marj, that has embraced refugees. "This kept the refugees from getting the aid they needed."
What really makes refugees politically radioactive is a painful national memory. Palestinians poured into Lebanon in 1948 and 1967, fleeing conflicts with Israel. Their arrival stoked sectarian divisions that helped ignite civil war. More than 400,000 Palestinians still live here, in camps with pockets of poverty and extremism where violence periodically erupts.
Bowing to fears of another destabilizing influx, the government ruled out camps for Syrians, provided limited help and gave international agencies little leeway. United Nations officials made the best of it, saying, perhaps wishfully, that at least refugees would be integrated into society. No one greeted Syrians at the border. Some joined relatives among 500,000 Syrian laborers already here. Others had no idea where to go, and followed word of mouth.
One of the warmest welcomes was in Saidnayel, the Sunni town in the central Bekaa, where the flag of the Syrian revolution flies openly. A year ago, it hosted 265 refugee families, their names recorded in a handwritten ledger.
"When they reach the borders, they ask for directions to Saidnayel," the mayor, Mr. Shubassi, said proudly then. "Each Friday we protest against the Syrian regime."
He squeezed one family into a bakery, others into a row of storage rooms. The Syrian Army was bombarding cities, and the mayor expected "an avalanche."
Still, he was buoyant. Local charities and mosques competed to help. Mr. Shubassi resented Syria's government, which occupied Lebanon in the civil war, and looked forward to its fall.
But as the influx accelerated, Lebanon's government cut off minimal cooperation with the understaffed United Nations refugee agency, which struggled to track scattered Syrians. Families seeking United Nations aid must register, a backlogged process that can take a month.
In Saidnayel, the mayor's ledger now lists 6,000 refugees, one for every five residents. Prices, rents and crime are up, wages down. Locals, poor themselves, are resentful. The family in the bakery has swollen from 10 to 40. They are incensed with the mayor's staff, which, they said, suggested they share two blankets.
As Syria's government hangs on, the mayor's optimism has deflated. "We don't know how long this will last," he said recently. "We will have a political and social rift."
Lebanon's government can no longer deny the crisis. Last month, Hezbollah urged Lebanese to welcome refugees regardless of sect or politics. The government reversed course, at least on paper. It approved plans to manage the crisis with help from the United Nations, which now awaits funds and permission to build two transit camps, each housing 5,000 refugees, a drop in the bucket.
Syrians and their hosts live edgily together, especially in non-Sunni areas. In the Christian village of Jezzine, where snowcapped peaks watch over red-roofed stone houses, 1,600 Syrian refugees outnumber residents.
"We don't know who they are," said Jezzine's representative in Parliament, Ziad Aswad, a Christian ally of Hezbollah. "They could be Al Qaeda."
Town officials interrogate Syrians about their politics and impose a 5 p.m. curfew. Mr. Aswad even warns, dramatically, that refugees could somehow take over the country: "Goodbye, Lebanon!"
But Abu Haidar, a Syrian Sunni who worked in Jezzine before the uprising, said employers helped him bring his family. He pointed at a bed, a stove and his room's only decoration, a picture of the Virgin Mary. "All this," he said, "is from the people of Jezzine."
In Tyre, the southern city where Roman ruins overlook the Mediterranean, Abdulfattah, 30, found safety from battles that ravaged his village in northern Syria. But he keeps his children inside his rented room. When he ventures out, he walks with watchful eyes and tense, hunched shoulders.
That is because this is pro-Assad territory. The streets flutter with yellow and green flags for Hezbollah. A short walk away, more than 25 of his relatives live in a two-room shack, awaiting United Nations aid.
Neighbors do not harass him, he said, nor do they offer help. Outside, Abdulfattah, who feared giving a last name, hides his views on the war. Indoors, he relaxed. "There is pain in every house," he said. "There is a martyr in every house."
He named his baby son for one of them, his brother, Rustom. "There are no new names," Abdulfattah said, hugging and kissing the baby. "Those who are dying are being reborn."
Dr. Darwish Shoughari, who runs the nonsectarian Amel clinic in Tyre, said southern Lebanon remained calm, thanks to residents' memories of sheltering in Syrian homes during Hezbollah's 2006 war with Israel, and to Hezbollah's tight grip on security.
"Hezbollah knows when a chicken lays an egg," he said.
"It's tolerable now," he added, with 30,000 refugees around a city of 135,000. "What happens when there are 100,000?"
Reporting was contributed by Hwaida Saad, Hania Mourtada, Ben Solomon and Lynsey Addario.
This article originally appeared in The New York Times.